The following equilibrium was studied by analyzing the equilibrium mixture for the amount of HCl produced.
LaCl3(s) + H2O(g) LaOCl(s) + 2HCl(g)
A vessel whose volume was 1.25 L was filled with 0.0125 mol of lanthanum(III) chloride, LaCl3, and 0.0250 mol H2O. After the mixture came to equilibrium in the closed vessel at 619ºC, the gaseous mixture was removed and dissolved in more water. Sufficient silver (I) ion was added to precipitate the chloride ion completely as silver chloride. If 3.59 g AgCl was obtained, what is the value of Kc at 619ºC?